dfgfggbr

11. Biomineralization
 Types & Uses
 Calcium carbonate
 Calcite & Aragonite (shells, lenses, gravity sensors)
 Vaterite (inner ear of two types of fish)
& Amorphous phases (Ca storage spindles in plants)
 Calcium phosphate (bones, teeth)
 Other Group 2A elements
 Silica (diatom & radiolarian micro shells)
 Iron oxides
 Metal sulfides
 While organic components may be only a few %, they
are critical to the important properties of the materials.

12. Calcium carbonate
Mineral Formula Organism Location Function
Calcite CaCO3 Foraminifera Shell Exoskeleton
Trilobite Eye lens Optics
Molluscs Shell Exoskeleton
Crustaceans Crab cuticle Mechanical strength
Birds Eggshells Protection
Mammals Inner ear Gravity receptor
Mg-calcite (Mg,Ca)CO3 Octocorals Spicules Mechanical strength
Echinoderms Shells/spines Protection
Aragonite CaCO3 Corals Cell wall Exoskeleton
Molluscs Shell Exoskeleton
Gastropods Love dart Reproduction
Cephalopods Shell Buoyancy
Fish Head Gravity receptor
Valerite CaCO3 Gastropods Shell Exoskeleton
Ascidians Spicules Protection
Amorphous CaCO3•H2O Crustateans Crab cuticle Mechanical strength
Plants Leaves Calcium storage

13. Different forms of CaCO3
www.solids.bnl.gov/ ~dimasi/bones/abalone/
 Calcite (prismatic)
 Hardness
 Aragonite (nacre)
 Toughness

14. Nacre layers
 Aragonite polygonal
tablets (500 nm thick).
 Protein/polysaccharide
organic matrix (30 nm
thick).

15. Calcium phosphate
 Hydroxyapatite Ca10(PO4)6(OH)2

Vertebrates
Mammals
Fish
Bone
Teeth
Scales

 Octacalcium phosphate Vertebrates
Bone/teeth precursor
 Ca8H2(PO4)6
 Amorphous various Chitons
Gastropods
Mammals
Teeth
Gizzard plates
Milk (ion storage)


Hydroxyapatite can also contain Sr, Mg, Na, CO3, etc.

16. n COMPSCI 296.5
Levels of bone
structure
Hydroxyapatite:
Crystalline calcium phosphate

17.  Gypsum
 Celestite
 Barite
CaSO4•2H2O Jellyfish gravityreceptor
SrSO4
BaSO4
Acantharia micro-skeleton
Loxedes gravity receptor
Group 2A

18. Magnetosomes in Bacteria
U. Heyen & D. Schler Growth and magnetosome formation by microaerophilic
Magnetospirillum strains in an oxygen-controlled fermentor Appl Microbiol
Biotechnol (2003) 61:536–544

19. Magnetosomes in Bacteria
(scale bars = 100 nm)
http://magnum.mpi-bremen.de/magneto/

20. LaBean COMPSCI 296.5LaBean
• COMPSCI 296.4